/*
    via686a.c - Part of lm_sensors, Linux kernel modules
                for hardware monitoring
                
    Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
                        Kyösti Mälkki <kmalkki@cc.hut.fi>,
			Mark Studebaker <mdsxyz123@yahoo.com>,
			and Bob Dougherty <bobd@stanford.edu>
    (Some conversion-factor data were contributed by Jonathan Teh Soon Yew 
    <j.teh@iname.com> and Alex van Kaam <darkside@chello.nl>.)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
    Supports the Via VT82C686A, VT82C686B south bridges.
    Reports all as a 686A.
    See doc/chips/via686a for details.
    Warning - only supports a single device.
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/i2c.h>
#include <linux/i2c-proc.h>
#include <linux/init.h>
#include <asm/io.h>
#include "version.h"
#include "sensors_compat.h"


/* If force_addr is set to anything different from 0, we forcibly enable
   the device at the given address. */
static int force_addr = 0;
MODULE_PARM(force_addr, "i");
MODULE_PARM_DESC(force_addr,
		 "Initialize the base address of the sensors");

/* Addresses to scan.
   Note that we can't determine the ISA address until we have initialized
   our module */
static unsigned short normal_i2c[] = { SENSORS_I2C_END };
static unsigned short normal_i2c_range[] = { SENSORS_I2C_END };
static unsigned int normal_isa[] = { 0x0000, SENSORS_ISA_END };
static unsigned int normal_isa_range[] = { SENSORS_ISA_END };

/* Insmod parameters */
SENSORS_INSMOD_1(via686a);

/*
   The Via 686a southbridge has a LM78-like chip integrated on the same IC.
   This driver is a customized copy of lm78.c
*/

/* Many VIA686A constants specified below */

/* Length of ISA address segment */
#define VIA686A_EXTENT 0x80
#define VIA686A_BASE_REG 0x70
#define VIA686A_ENABLE_REG 0x74

/* The VIA686A registers */
/* ins numbered 0-4 */
#define VIA686A_REG_IN_MAX(nr) (0x2b + ((nr) * 2))
#define VIA686A_REG_IN_MIN(nr) (0x2c + ((nr) * 2))
#define VIA686A_REG_IN(nr)     (0x22 + (nr))

/* fans numbered 1-2 */
#define VIA686A_REG_FAN_MIN(nr) (0x3a + (nr))
#define VIA686A_REG_FAN(nr)     (0x28 + (nr))

// the following values are as speced by VIA:
static const u8 regtemp[] = { 0x20, 0x21, 0x1f };
static const u8 regover[] = { 0x39, 0x3d, 0x1d };
static const u8 reghyst[] = { 0x3a, 0x3e, 0x1e };

/* temps numbered 1-3 */
#define VIA686A_REG_TEMP(nr)		(regtemp[(nr) - 1])
#define VIA686A_REG_TEMP_OVER(nr)	(regover[(nr) - 1])
#define VIA686A_REG_TEMP_HYST(nr)	(reghyst[(nr) - 1])
#define VIA686A_REG_TEMP_LOW1	0x4b	// bits 7-6
#define VIA686A_REG_TEMP_LOW23	0x49	// 2 = bits 5-4, 3 = bits 7-6

#define VIA686A_REG_ALARM1 0x41
#define VIA686A_REG_ALARM2 0x42
#define VIA686A_REG_FANDIV 0x47
#define VIA686A_REG_CONFIG 0x40
// The following register sets temp interrupt mode (bits 1-0 for temp1, 
// 3-2 for temp2, 5-4 for temp3).  Modes are:
//    00 interrupt stays as long as value is out-of-range
//    01 interrupt is cleared once register is read (default)
//    10 comparator mode- like 00, but ignores hysteresis
//    11 same as 00
#define VIA686A_REG_TEMP_MODE 0x4b
// We'll just assume that you want to set all 3 simultaneously:
#define VIA686A_TEMP_MODE_MASK 0x3F
#define VIA686A_TEMP_MODE_CONTINUOUS (0x00)

/* Conversions. Limit checking is only done on the TO_REG
   variants. */

/********* VOLTAGE CONVERSIONS (Bob Dougherty) ********/
// From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
// voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
// voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
// voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
// voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
// voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
// in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
// That is:
// volts = (25*regVal+133)*factor
// regVal = (volts/factor-133)/25
// (These conversions were contributed by Jonathan Teh Soon Yew 
// <j.teh@iname.com>)
static inline u8 IN_TO_REG(long val, int inNum)
{
	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
	   Rounding is done (120500 is actually 133000 - 12500).
	   Remember that val is expressed in 0.01V/bit, which is why we divide
	   by an additional 1000 (10000 for +12V): 100 for val and 10 (100)
	   for the constants. */
	if (inNum <= 1)
		return (u8)
		    SENSORS_LIMIT((val * 21024 - 120500) / 25000, 0, 255);
	else if (inNum == 2)
		return (u8)
		    SENSORS_LIMIT((val * 15737 - 120500) / 25000, 0, 255);
	else if (inNum == 3)
		return (u8)
		    SENSORS_LIMIT((val * 10108 - 120500) / 25000, 0, 255);
	else
		return (u8)
		    SENSORS_LIMIT((val * 41714 - 1205000) / 250000, 0, 255);
}

static inline long IN_FROM_REG(u8 val, int inNum)
{
	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
	   We also multiply them by 100 because we want 0.01V/bit for the
	   output value. Rounding is done. */
	if (inNum <= 1)
		return (long) ((25000 * val + 133000 + 21024 / 2) / 21024);
	else if (inNum == 2)
		return (long) ((25000 * val + 133000 + 15737 / 2) / 15737);
	else if (inNum == 3)
		return (long) ((25000 * val + 133000 + 10108 / 2) / 10108);
	else
		return (long) ((250000 * val + 1330000 + 41714 / 2) / 41714);
}

/********* FAN RPM CONVERSIONS ********/
// Higher register values = slower fans (the fan's strobe gates a counter).
// But this chip saturates back at 0, not at 255 like all the other chips.
// So, 0 means 0 RPM
static inline u8 FAN_TO_REG(long rpm, int div)
{
	if (rpm == 0)
		return 0;
	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
}

#define FAN_FROM_REG(val,div) ((val)==0?0:(val)==255?0:1350000/((val)*(div)))

/******** TEMP CONVERSIONS (Bob Dougherty) *********/
// linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
//      if(temp<169)
//              return double(temp)*0.427-32.08;
//      else if(temp>=169 && temp<=202)
//              return double(temp)*0.582-58.16;
//      else
//              return double(temp)*0.924-127.33;
//
// A fifth-order polynomial fits the unofficial data (provided by Alex van 
// Kaam <darkside@chello.nl>) a bit better.  It also give more reasonable 
// numbers on my machine (ie. they agree with what my BIOS tells me).  
// Here's the fifth-order fit to the 8-bit data:
// temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 - 
//        2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
//
// (2000-10-25- RFD: thanks to Uwe Andersen <uandersen@mayah.com> for 
// finding my typos in this formula!)
//
// Alas, none of the elegant function-fit solutions will work because we 
// aren't allowed to use floating point in the kernel and doing it with 
// integers doesn't provide enough precision.  So we'll do boring old 
// look-up table stuff.  The unofficial data (see below) have effectively 
// 7-bit resolution (they are rounded to the nearest degree).  I'm assuming 
// that the transfer function of the device is monotonic and smooth, so a 
// smooth function fit to the data will allow us to get better precision.  
// I used the 5th-order poly fit described above and solved for
// VIA register values 0-255.  I *10 before rounding, so we get tenth-degree 
// precision.  (I could have done all 1024 values for our 10-bit readings, 
// but the function is very linear in the useful range (0-80 deg C), so 
// we'll just use linear interpolation for 10-bit readings.)  So, tempLUT 
// is the temp at via register values 0-255:
static const s16 tempLUT[] =
    { -709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
	    -503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
	    -362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
	    -255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
	    -173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
	    -108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
	    -44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
	    20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
	    88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
	    142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
	    193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
	    245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
	    299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
	    353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
	    409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
	    469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
	    538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
	    621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
	    728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
	    870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
	    1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
	    1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
};

/* the original LUT values from Alex van Kaam <darkside@chello.nl> 
   (for via register values 12-240):
{-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
-30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
-15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
-3,-2,-2,-1,-1,0,0,1,1,1,3,3,3,4,4,4,5,5,5,6,6,7,7,8,8,9,9,9,10,10,11,11,12,
12,12,13,13,13,14,14,15,15,16,16,16,17,17,18,18,19,19,20,20,21,21,21,22,22,
22,23,23,24,24,25,25,26,26,26,27,27,27,28,28,29,29,30,30,30,31,31,32,32,33,
33,34,34,35,35,35,36,36,37,37,38,38,39,39,40,40,41,41,42,42,43,43,44,44,45,
45,46,46,47,48,48,49,49,50,51,51,52,52,53,53,54,55,55,56,57,57,58,59,59,60,
61,62,62,63,64,65,66,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,83,84,
85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
*/

// Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
// an extra term for a good fit to these inverse data!) and then 
// solving for each temp value from -50 to 110 (the useable range for 
// this chip).  Here's the fit: 
// viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4 
// - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
// Note that n=161:
static const u8 viaLUT[] =
    { 12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
	    23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
	    41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
	    69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
	    103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
	    131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
	    158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
	    182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
	    200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
	    214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
	    225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
	    233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
	    239, 240
};

/* Converting temps to (8-bit) hyst and over registers
   No interpolation here.
   The +50 is because the temps start at -50 */
static inline u8 TEMP_TO_REG(long val)
{
	return viaLUT[val <= -500 ? 0 : val >= 1100 ? 160 : 
		      (val < 0 ? val - 5 : val + 5) / 10 + 50];
}

/* for 8-bit temperature hyst and over registers */
#define TEMP_FROM_REG(val) (tempLUT[(val)])

/* for 10-bit temperature readings */
// You might _think_ this is too long to inline, but's it's really only
// called once...
static inline long TEMP_FROM_REG10(u16 val)
{
	// the temp values are already *10, so we don't need to do that.
	long temp;
	u16 eightBits = val >> 2;
	u16 twoBits = val & 3;

	/* no interpolation for these */
	if (twoBits == 0 || eightBits == 255)
		return (long) tempLUT[eightBits];

	/* do some linear interpolation */
	temp = (4 - twoBits) * tempLUT[eightBits]
	     + twoBits * tempLUT[eightBits + 1];
	/* achieve rounding */
	return (temp < 0 ? temp - 2 : temp + 2) / 4;
}

#define ALARMS_FROM_REG(val) (val)

#define DIV_FROM_REG(val) (1 << (val))
#define DIV_TO_REG(val) ((val)==8?3:(val)==4?2:(val)==1?0:1)

/* For the VIA686A, we need to keep some data in memory.
   The structure is dynamically allocated, at the same time when a new
   via686a client is allocated. */
struct via686a_data {
	struct i2c_client client;
	struct semaphore lock;
	int sysctl_id;

	struct semaphore update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	u8 in[5];		/* Register value */
	u8 in_max[5];		/* Register value */
	u8 in_min[5];		/* Register value */
	u8 fan[2];		/* Register value */
	u8 fan_min[2];		/* Register value */
	u16 temp[3];		/* Register value 10 bit */
	u8 temp_over[3];	/* Register value */
	u8 temp_hyst[3];	/* Register value */
	u8 fan_div[2];		/* Register encoding, shifted right */
	u16 alarms;		/* Register encoding, combined */
};

static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */

static int via686a_attach_adapter(struct i2c_adapter *adapter);
static int via686a_detect(struct i2c_adapter *adapter, int address,
			  unsigned short flags, int kind);
static int via686a_detach_client(struct i2c_client *client);

static int via686a_read_value(struct i2c_client *client, u8 register);
static void via686a_write_value(struct i2c_client *client, u8 register,
				u8 value);
static void via686a_update_client(struct i2c_client *client);
static void via686a_init_client(struct i2c_client *client);


static void via686a_in(struct i2c_client *client, int operation,
		       int ctl_name, int *nrels_mag, long *results);
static void via686a_fan(struct i2c_client *client, int operation,
			int ctl_name, int *nrels_mag, long *results);
static void via686a_temp(struct i2c_client *client, int operation,
			 int ctl_name, int *nrels_mag, long *results);
static void via686a_alarms(struct i2c_client *client, int operation,
			   int ctl_name, int *nrels_mag, long *results);
static void via686a_fan_div(struct i2c_client *client, int operation,
			    int ctl_name, int *nrels_mag, long *results);

/* The driver. I choose to use type i2c_driver, as at is identical to both
   smbus_driver and isa_driver, and clients could be of either kind */
static struct i2c_driver via686a_driver = {
	.name		= "VIA 686A",
	.id		= I2C_DRIVERID_VIA686A,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= via686a_attach_adapter,
	.detach_client	= via686a_detach_client,
};



/* The /proc/sys entries */

/* -- SENSORS SYSCTL START -- */
#define VIA686A_SYSCTL_IN0 1000
#define VIA686A_SYSCTL_IN1 1001
#define VIA686A_SYSCTL_IN2 1002
#define VIA686A_SYSCTL_IN3 1003
#define VIA686A_SYSCTL_IN4 1004
#define VIA686A_SYSCTL_FAN1 1101
#define VIA686A_SYSCTL_FAN2 1102
#define VIA686A_SYSCTL_TEMP 1200
#define VIA686A_SYSCTL_TEMP2 1201
#define VIA686A_SYSCTL_TEMP3 1202
#define VIA686A_SYSCTL_FAN_DIV 2000
#define VIA686A_SYSCTL_ALARMS 2001

#define VIA686A_ALARM_IN0 0x01
#define VIA686A_ALARM_IN1 0x02
#define VIA686A_ALARM_IN2 0x04
#define VIA686A_ALARM_IN3 0x08
#define VIA686A_ALARM_TEMP 0x10
#define VIA686A_ALARM_FAN1 0x40
#define VIA686A_ALARM_FAN2 0x80
#define VIA686A_ALARM_IN4 0x100
#define VIA686A_ALARM_TEMP2 0x800
#define VIA686A_ALARM_CHAS 0x1000
#define VIA686A_ALARM_TEMP3 0x8000

/* -- SENSORS SYSCTL END -- */

/* These files are created for each detected VIA686A. This is just a template;
   though at first sight, you might think we could use a statically
   allocated list, we need some way to get back to the parent - which
   is done through one of the 'extra' fields which are initialized 
   when a new copy is allocated. */
static ctl_table via686a_dir_table_template[] = {
	{VIA686A_SYSCTL_IN0, "in0", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_in},
	{VIA686A_SYSCTL_IN1, "in1", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_in},
	{VIA686A_SYSCTL_IN2, "in2", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_in},
	{VIA686A_SYSCTL_IN3, "in3", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_in},
	{VIA686A_SYSCTL_IN4, "in4", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_in},
	{VIA686A_SYSCTL_FAN1, "fan1", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_fan},
	{VIA686A_SYSCTL_FAN2, "fan2", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_fan},
	{VIA686A_SYSCTL_TEMP, "temp1", NULL, 0, 0644, NULL, &i2c_proc_real,
	 &i2c_sysctl_real, NULL, &via686a_temp},
	{VIA686A_SYSCTL_TEMP2, "temp2", NULL, 0, 0644, NULL,
	 &i2c_proc_real, &i2c_sysctl_real, NULL, &via686a_temp},
	{VIA686A_SYSCTL_TEMP3, "temp3", NULL, 0, 0644, NULL,
	 &i2c_proc_real, &i2c_sysctl_real, NULL, &via686a_temp},
	{VIA686A_SYSCTL_FAN_DIV, "fan_div", NULL, 0, 0644, NULL,
	 &i2c_proc_real, &i2c_sysctl_real, NULL, &via686a_fan_div},
	{VIA686A_SYSCTL_ALARMS, "alarms", NULL, 0, 0444, NULL,
	 &i2c_proc_real, &i2c_sysctl_real, NULL, &via686a_alarms},
	{0}
};

static inline int via686a_read_value(struct i2c_client *client, u8 reg)
{
	return (inb_p(client->addr + reg));
}

static inline void via686a_write_value(struct i2c_client *client, u8 reg,
				       u8 value)
{
	outb_p(value, client->addr + reg);
}

/* This is called when the module is loaded */
static int via686a_attach_adapter(struct i2c_adapter *adapter)
{
	return i2c_detect(adapter, &addr_data, via686a_detect);
}

int via686a_detect(struct i2c_adapter *adapter, int address,
		   unsigned short flags, int kind)
{
	int i;
	struct i2c_client *new_client;
	struct via686a_data *data;
	int err = 0;
	const char *type_name = "via686a";
	u16 val;

	/* Make sure we are probing the ISA bus!!  */
	if (!i2c_is_isa_adapter(adapter)) {
		printk
		("via686a.o: via686a_detect called for an I2C bus adapter?!?\n");
		return 0;
	}

	/* 8231 requires multiple of 256, we enforce that on 686 as well */
	if(force_addr)
		address = force_addr & 0xFF00;
	if (check_region(address, VIA686A_EXTENT)) {
		printk("via686a.o: region 0x%x already in use!\n",
		       address);
		return -ENODEV;
	}

	if(force_addr) {
		printk("via686a.o: forcing ISA address 0x%04X\n", address);
		if (PCIBIOS_SUCCESSFUL !=
		    pci_write_config_word(s_bridge, VIA686A_BASE_REG, address))
			return -ENODEV;
	}
	if (PCIBIOS_SUCCESSFUL !=
	    pci_read_config_word(s_bridge, VIA686A_ENABLE_REG, &val))
		return -ENODEV;
	if (!(val & 0x0001)) {
		printk("via686a.o: enabling sensors\n");
		if (PCIBIOS_SUCCESSFUL !=
		    pci_write_config_word(s_bridge, VIA686A_ENABLE_REG,
		                      val | 0x0001))
			return -ENODEV;
	}

	if (!(data = kmalloc(sizeof(struct via686a_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto ERROR0;
	}

	new_client = &data->client;
	new_client->addr = address;
	init_MUTEX(&data->lock);
	new_client->data = data;
	new_client->adapter = adapter;
	new_client->driver = &via686a_driver;
	new_client->flags = 0;

	/* Reserve the ISA region */
	request_region(address, VIA686A_EXTENT, "via686a-sensors");

	/* Fill in the remaining client fields and put into the global list */
	strcpy(new_client->name, "Via 686A Integrated Sensors");
	data->valid = 0;
	init_MUTEX(&data->update_lock);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
		goto ERROR3;

	/* Register a new directory entry with module sensors */
	if ((i = i2c_register_entry((struct i2c_client *) new_client,
					type_name,
					via686a_dir_table_template,
					THIS_MODULE)) < 0) {
		err = i;
		goto ERROR4;
	}
	data->sysctl_id = i;

	/* Initialize the VIA686A chip */
	via686a_init_client(new_client);
	return 0;

      ERROR4:
	i2c_detach_client(new_client);
      ERROR3:
	release_region(address, VIA686A_EXTENT);
	kfree(data);
      ERROR0:
	return err;
}

static int via686a_detach_client(struct i2c_client *client)
{
	int err;

	i2c_deregister_entry(((struct via686a_data *) 
				  (client->data))->sysctl_id);

	if ((err = i2c_detach_client(client))) {
		printk
		("via686a.o: Client deregistration failed, client not detached.\n");
		return err;
	}

	release_region(client->addr, VIA686A_EXTENT);
	kfree(client->data);

	return 0;
}

/* Called when we have found a new VIA686A. */
static void via686a_init_client(struct i2c_client *client)
{
	u8 reg;

	/* Start monitoring */
	reg = via686a_read_value(client, VIA686A_REG_CONFIG);
	via686a_write_value(client, VIA686A_REG_CONFIG, (reg|0x01)&0x7F);

	/* Configure temp interrupt mode for continuous-interrupt operation */
	via686a_write_value(client, VIA686A_REG_TEMP_MODE, 
			    via686a_read_value(client, VIA686A_REG_TEMP_MODE) &
			    !(VIA686A_TEMP_MODE_MASK | VIA686A_TEMP_MODE_CONTINUOUS));
}

static void via686a_update_client(struct i2c_client *client)
{
	struct via686a_data *data = client->data;
	int i;

	down(&data->update_lock);

       if (time_after(jiffies - data->last_updated, HZ + HZ / 2) ||
           time_before(jiffies, data->last_updated) || !data->valid) {

		for (i = 0; i <= 4; i++) {
			data->in[i] =
			    via686a_read_value(client, VIA686A_REG_IN(i));
			data->in_min[i] = via686a_read_value(client,
							     VIA686A_REG_IN_MIN
							     (i));
			data->in_max[i] =
			    via686a_read_value(client, VIA686A_REG_IN_MAX(i));
		}
		for (i = 1; i <= 2; i++) {
			data->fan[i - 1] =
			    via686a_read_value(client, VIA686A_REG_FAN(i));
			data->fan_min[i - 1] = via686a_read_value(client,
						     VIA686A_REG_FAN_MIN(i));
		}
		for (i = 1; i <= 3; i++) {
			data->temp[i - 1] = via686a_read_value(client,
						 VIA686A_REG_TEMP(i)) << 2;
			data->temp_over[i - 1] =
			    via686a_read_value(client,
					       VIA686A_REG_TEMP_OVER(i));
			data->temp_hyst[i - 1] =
			    via686a_read_value(client,
					       VIA686A_REG_TEMP_HYST(i));
		}
		/* add in lower 2 bits 
		   temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
		   temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
		   temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
		 */
		data->temp[0] |= (via686a_read_value(client,
						     VIA686A_REG_TEMP_LOW1)
				  & 0xc0) >> 6;
		data->temp[1] |=
		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
		     0x30) >> 4;
		data->temp[2] |=
		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
		     0xc0) >> 6;

		i = via686a_read_value(client, VIA686A_REG_FANDIV);
		data->fan_div[0] = (i >> 4) & 0x03;
		data->fan_div[1] = i >> 6;
		data->alarms =
		    via686a_read_value(client,
				       VIA686A_REG_ALARM1) |
		    (via686a_read_value(client, VIA686A_REG_ALARM2) << 8);
		data->last_updated = jiffies;
		data->valid = 1;
	}

	up(&data->update_lock);
}


/* The next few functions are the call-back functions of the /proc/sys and
   sysctl files. Which function is used is defined in the ctl_table in
   the extra1 field.
   Each function must return the magnitude (power of 10 to divide the date
   with) if it is called with operation==SENSORS_PROC_REAL_INFO. It must
   put a maximum of *nrels elements in results reflecting the data of this
   file, and set *nrels to the number it actually put in it, if operation==
   SENSORS_PROC_REAL_READ. Finally, it must get upto *nrels elements from
   results and write them to the chip, if operations==SENSORS_PROC_REAL_WRITE.
   Note that on SENSORS_PROC_REAL_READ, I do not check whether results is
   large enough (by checking the incoming value of *nrels). This is not very
   good practice, but as long as you put less than about 5 values in results,
   you can assume it is large enough. */
static void via686a_in(struct i2c_client *client, int operation, int ctl_name,
               int *nrels_mag, long *results)
{
	struct via686a_data *data = client->data;
	int nr = ctl_name - VIA686A_SYSCTL_IN0;

	if (operation == SENSORS_PROC_REAL_INFO)
		*nrels_mag = 2;
	else if (operation == SENSORS_PROC_REAL_READ) {
		via686a_update_client(client);
		results[0] = IN_FROM_REG(data->in_min[nr], nr);
		results[1] = IN_FROM_REG(data->in_max[nr], nr);
		results[2] = IN_FROM_REG(data->in[nr], nr);
		*nrels_mag = 3;
	} else if (operation == SENSORS_PROC_REAL_WRITE) {
		if (*nrels_mag >= 1) {
			data->in_min[nr] = IN_TO_REG(results[0], nr);
			via686a_write_value(client, VIA686A_REG_IN_MIN(nr),
					    data->in_min[nr]);
		}
		if (*nrels_mag >= 2) {
			data->in_max[nr] = IN_TO_REG(results[1], nr);
			via686a_write_value(client, VIA686A_REG_IN_MAX(nr),
					    data->in_max[nr]);
		}
	}
}

void via686a_fan(struct i2c_client *client, int operation, int ctl_name,
		 int *nrels_mag, long *results)
{
	struct via686a_data *data = client->data;
	int nr = ctl_name - VIA686A_SYSCTL_FAN1 + 1;

	if (operation == SENSORS_PROC_REAL_INFO)
		*nrels_mag = 0;
	else if (operation == SENSORS_PROC_REAL_READ) {
		via686a_update_client(client);
		results[0] = FAN_FROM_REG(data->fan_min[nr - 1],
					  DIV_FROM_REG(data->fan_div
						       [nr - 1]));
		results[1] = FAN_FROM_REG(data->fan[nr - 1],
				 DIV_FROM_REG(data->fan_div[nr - 1]));
		*nrels_mag = 2;
	} else if (operation == SENSORS_PROC_REAL_WRITE) {
		if (*nrels_mag >= 1) {
			data->fan_min[nr - 1] = FAN_TO_REG(results[0], 
							   DIV_FROM_REG(data->
							      fan_div[nr -1]));
			via686a_write_value(client,
					    VIA686A_REG_FAN_MIN(nr),
					    data->fan_min[nr - 1]);
		}
	}
}

void via686a_temp(struct i2c_client *client, int operation, int ctl_name,
		  int *nrels_mag, long *results)
{
	struct via686a_data *data = client->data;
	int nr = ctl_name - VIA686A_SYSCTL_TEMP;

	if (operation == SENSORS_PROC_REAL_INFO)
		*nrels_mag = 1;
	else if (operation == SENSORS_PROC_REAL_READ) {
		via686a_update_client(client);
		results[0] = TEMP_FROM_REG(data->temp_over[nr]);
		results[1] = TEMP_FROM_REG(data->temp_hyst[nr]);
		results[2] = TEMP_FROM_REG10(data->temp[nr]);
		*nrels_mag = 3;
	} else if (operation == SENSORS_PROC_REAL_WRITE) {
		if (*nrels_mag >= 1) {
			data->temp_over[nr] = TEMP_TO_REG(results[0]);
			via686a_write_value(client,
					    VIA686A_REG_TEMP_OVER(nr + 1),
					    data->temp_over[nr]);
		}
		if (*nrels_mag >= 2) {
			data->temp_hyst[nr] = TEMP_TO_REG(results[1]);
			via686a_write_value(client,
					    VIA686A_REG_TEMP_HYST(nr + 1),
					    data->temp_hyst[nr]);
		}
	}
}

void via686a_alarms(struct i2c_client *client, int operation, int ctl_name,
		    int *nrels_mag, long *results)
{
	struct via686a_data *data = client->data;
	if (operation == SENSORS_PROC_REAL_INFO)
		*nrels_mag = 0;
	else if (operation == SENSORS_PROC_REAL_READ) {
		via686a_update_client(client);
		results[0] = ALARMS_FROM_REG(data->alarms);
		*nrels_mag = 1;
	}
}

void via686a_fan_div(struct i2c_client *client, int operation,
		     int ctl_name, int *nrels_mag, long *results)
{
	struct via686a_data *data = client->data;
	int old;

	if (operation == SENSORS_PROC_REAL_INFO)
		*nrels_mag = 0;
	else if (operation == SENSORS_PROC_REAL_READ) {
		via686a_update_client(client);
		results[0] = DIV_FROM_REG(data->fan_div[0]);
		results[1] = DIV_FROM_REG(data->fan_div[1]);
		*nrels_mag = 2;
	} else if (operation == SENSORS_PROC_REAL_WRITE) {
		old = via686a_read_value(client, VIA686A_REG_FANDIV);
		if (*nrels_mag >= 2) {
			data->fan_div[1] = DIV_TO_REG(results[1]);
			old = (old & 0x3f) | (data->fan_div[1] << 6);
		}
		if (*nrels_mag >= 1) {
			data->fan_div[0] = DIV_TO_REG(results[0]);
			old = (old & 0xcf) | (data->fan_div[0] << 4);
			via686a_write_value(client, VIA686A_REG_FANDIV,
					    old);
		}
	}
}


static struct pci_device_id via686a_pci_ids[] __devinitdata = {
       {PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
       { 0, }
};

static int __devinit via686a_pci_probe(struct pci_dev *dev,
                                      const struct pci_device_id *id)
{
       u16 val;
       int addr = 0;

       if (PCIBIOS_SUCCESSFUL !=
           pci_read_config_word(dev, VIA686A_BASE_REG, &val))
               return -ENODEV;

       addr = val & ~(VIA686A_EXTENT - 1);
       if (addr == 0 && force_addr == 0) {
               printk("via686a.o: base address not set - upgrade BIOS or use force_addr=0xaddr\n");
               return -ENODEV;
       }
       if (force_addr)
               addr = force_addr;      /* so detect will get called */

       normal_isa[0] = addr;
       s_bridge = dev;
       return i2c_add_driver(&via686a_driver);
}

static void __devexit via686a_pci_remove(struct pci_dev *dev)
{
       i2c_del_driver(&via686a_driver);
}

static struct pci_driver via686a_pci_driver = {
       .name		= "via686a",
       .id_table	= via686a_pci_ids,
       .probe		= via686a_pci_probe,
       .remove		= __devexit_p(via686a_pci_remove),
};

static int __init sm_via686a_init(void)
{
	printk("via686a.o version %s (%s)\n", LM_VERSION, LM_DATE);
	return pci_module_init(&via686a_pci_driver);
}

static void __exit sm_via686a_exit(void)
{
       pci_unregister_driver(&via686a_pci_driver);
}

MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>, "
              "Mark Studebaker <mdsxyz123@yahoo.com> "
             "and Bob Dougherty <bobd@stanford.edu>");
MODULE_DESCRIPTION("VIA 686A Sensor device");
MODULE_LICENSE("GPL");

module_init(sm_via686a_init);
module_exit(sm_via686a_exit);
